The first total syntheses of prephenic acid, epiprehenic acid, dihydroprephenic acid, dihydroepiprephenic acid, tetrahydroprephenic acid and tetrahydroepiprephenic acid have been achieved. Capitalizing on these syntheses we will determine the enzymic recognition and/or inhibitory powers of the epi compounds and the reduced versions of the prephenates in the biosynthesis of aromatic amino acids (phenylalanine and tyrosine). The first total synthesis of pentalenolactone has been accomplished. One is now in a position to investigate the effect of structural and stereochemical modifications on biological activity. The chemistry which was used successfully in the prephenate series allowed us to complete, very rapidly, a synthesis of the antifungal agent griseofulvin. We hope to apply this methodology further to embrace a synthesis to the macrolide antibiotic, lasiodipilodin. Some early attempts at the synthesis of bicyclomycin are also envisioned.